1. Field of the Invention
The present invention generally relates to a reverse prevention mechanism and, more specifically, to a reverse prevention mechanism for a lever drag reel for preventing reverse rotation (i.e., rotation in a line-releasing direction) of a drag disk receiving transmission of rotation of a handle via a pinion gear by braking a spool capable of rotating with respect to a reel unit.
2. Background Information
The dual-bearing reel is classified into a lever drag reel and a star drag reel. The lever drag reel is configured to brake rotation of a spool in a line-releasing direction with a drag lever. The drag lever is attached to a handle attachment side of a reel unit. The drag lever is capable of pivoting around a spool shaft. On the other hand, the star drag reel is configured to brake the spool with a star drag. The star drag is capable of rotating around a handle shaft.
In general, the lever drag reel is provided with a reverse prevention mechanism for applying the drag force to a spool when the spool rotates in the line-releasing direction. The reverse prevention mechanism includes a one-way clutch for preventing rotation of the drag disk in the line-releasing direction. The drag disk is capable of making contact with the spool.
The reverse prevention mechanism for the lever drag reel is generally mounted to a handle shaft. Specifically, the reverse prevention mechanism is mounted to the handle shaft for integrally rotating with the handle shaft. The reverse prevention mechanism includes a rotation member, a pawl member, and an urging member. The rotation member is arranged along with a main gear. An example of the rotation member is a ratchet wheel. The pawl member is pivotally mounted to the reel unit for engaging with the rotation member. The urging member urges the pawl member toward the engagement position. For example, Japan Patent Application Publication No. JP-A-H10-313751 discloses the above-mentioned configuration.
According to the reverse prevention mechanism, when the spool rotates in the line-releasing direction, the drag force is transmitted from the drag disk to the rotation member mounted to the handle shaft via a pinion gear and the main gear. The pawl member subsequently engages with the rotation member. Thus, the engaged rotation member and the pawl member receive the load in the application of the drag force.
On the other hand, some lever drag reels are configured to switch rotation speed of the handle between high and low levels (hereinafter referred to as “two-stage variable-speed lever drag reel”). In the lever drag reels of this type, a mechanism for switching the rotation speed of the handle is arranged in the interior of the handle shaft. Accordingly, the structure of the handle shaft will be complex and the strength thereof will be lowered. Consequently, it is quite difficult to attach a ratchet wheel to the handle shaft. In response to the structural problem, the two-stage variable-speed lever drag reel is configured to prevent rotation of the drag disk in the line-releasing direction with a large-diameter pinion gear of two pinion gears meshing with two main gears. Japan Patent Application Publication No. JP-A-2004-236586 discloses the configuration.
The conventional reverse prevention mechanism with a pinion gear includes a pawl member and an urging member. The pawl member is coupled to the reel unit, and is capable of pivoting in an engagement position and a remote position. The pawl member is engaged with a large-diameter part of the pinion gear on the engagement position while the pawl member is detached and away from the pinion gear on the remote position. The urging member urges the pawl member toward the engagement position. The pinion gear includes a tubular shaft portion and gear teeth. The spool shaft penetrates the shaft portion of the pinion gear. Diameter of the gear teeth is larger than that of the shaft potion. An engagement portion is formed on the shaft portion, and the engagement portion is engaged with the drag disk. Accordingly, the pinion gear is capable of integrally rotating with the drag disk. With the mesh between the pinion gear and the pawl member, it is possible to simplify the structure of the reverse rotation mechanism without complicating the structure of the handle shaft.
However, according to the conventional art of the former publication, the one-way clutch is mounted to the handle shaft. Therefore, strong force will be applied to the mesh between the pinion gear and the main gear in the application of the drag force. Accordingly, gear teeth of the pinion gear receive excessive force in the application of the drag force, and may be damaged.
On the other hand, according to the conventional art of the latter publication, engagement between the pinion gear and the pawl member prevents reverse rotation of the drag disk. Accordingly, the pinion gear and the pawl member may receive large load in the application of the drag force. In response to this, the latter conventional art produces the configuration that the pawl member is engaged with the large-diameter pinion gear. The large-diameter pinion gear has gear teeth with higher strength than those of the small-diameter pinion gear.
However, when the lever drag reel is compactly formed, the number of the gear teeth of the large-diameter pinion gear will be accordingly reduced and diameter of the pinion gear will be reduced. Therefore, strength of the gear teeth will be lowered. When large drag force is applied while the pawl member is engaged with the pinion gear, the gear teeth will be possibly damaged.